text: Specifically, an SMB system has two or more identical columns, which are connected to the mobile phase pump, and each other, by a multi-port valve. The plumbing is configured in such a way that:
  :a) all columns will be connected in series, forming a single continuous loop;
  :b) typically, between each column there will be provisions for four process streams: incoming feed mixture, exiting purified fast component, exiting purified slow component, and incoming solvent or eluent;
  and
  :c) each process stream (two inlets and two outlets) will proceed in the same direction after a set time (the steptime).